1. Field of the Invention
The present invention relates to an electromagnetic fuel injection valve suitable for use in an engine for an automobile or the like, and more particularly, to an electromagnetic fuel injection valve structure which exhibits excellent response and atomization characteristics.
2. Description of the Related Art
Conventional electromagnetic fuel injection valve of the type which includes a disk-shaped movable member as a valve body have been proposed in the specification of, for example, International Publication No. WO 88/04727. This electromagnetic fuel injection valve uses a lightweight movable portion and therefore exhibits quick response. In this fuel injection valve, a valve seat, which is disposed opposite the valve body, has only an injection hole formed therein. Hence, motion only in an axial direction is imparted to the fuel while it is passing through the injection hole.
Thus, in the above-described conventional device, although the movable portion is lightweight and quick response can therefore be achieved, no consideration is given to the control of the atomization of the fuel and of the form into which the fuel is atomized, raising problems concerning the response and the ease with which an engine can be started at a low temperature. More specifically, fuel which is under a pressure (2 to 4 kgf/cm.sup.2) normally employed in a gasoline engine is atomized such that it has an average particle diameter of 300 .mu.m or above. This means the atomized fuel is seen not as a spray but as a shower. Furthermore, the spray is not diffused and has only a bar-like shape. Furthermore, a deposit is readily formed on the injection hole when a substitute for gasoline is used.
In order to allow an electromagnetic fuel injection valve to be employed in various types of engines, there has been a demand for an electromagnetic fuel injection valve which exhibits excellent fuel atomization and which enables the form into which the fuel is sprayed to be selected flexibly.